2.2.0 Throws Exception for class with custom metaclass

[b-phi]

Handler <function process_docstring at 0x7f12ae4c8b80> for event 'autodoc-process-docstring' threw an exception (exception: unhashable type: '_SchemaMeta')

I've including the relevant skeleton of the classes below.

class _SchemaMeta(type):
    def __new__(mcs, *args: Any, **kwargs: Any) -> '_SchemaMeta':
        # some logic
        return schema_cls

    def __eq__(cls, other: Any) -> bool:
        ...

class Schema(metaclass=_SchemaMeta):
    ...

Elsewhere in the code, we have this which causes the error

class Foo:
    def do_something(self, schema: Schema) -> None:
        """
        Args:
            schema: Some schema.
        """
        ...

Edit: I've pinned to 2.1.1 for now, which doesn't throw an error in this case.

[hoodmane]

@tikuma-lsuhsc seems likely a regression caused by #459.

[tikuma-lsuhsc]

Yep, I did not account for a string annotation as I wasn't even aware such is even an option. I'll look into it tonight.

[tikuma-lsuhsc]

@b-phi - I tested all three class def's of yours but none produced the error that you reported.

Built with sphinxcontrib-restbuilder (for convenience as I'm using it for my current project), your code snippet produced the following without any error or warning.

**class mod._SchemaMeta(*args: Any, **kwargs: Any)**

**class mod.Schema**

**class mod.Foo**

   **do_something(mod: Schema) -> None**

      :Parameters:
         **schema** (`Schema <#mod.Schema>`_) – Some
         schema.

      :Return type:
         ``None``

with the autodoc command in the input rst file:

.. autoclass:: mod._SchemaMeta
   :members:

.. autoclass::  mod.Schema
   :members:

.. autoclass::  mod.Foo
   :members:

I've also written pytest cases within the repo without any success. Could you disclose more info? (relevant conf.py entry & the rst lines come to my mind). Thanks.

[bartfeenstra]

I am getting the following, very similar error:

Extension error (sphinx_autodoc_typehints):
Handler <function process_docstring at 0x7e7cf5e92520> for event 'autodoc-process-docstring' threw an exception (exception: unhashable type: 'typing.ParamSpecArgs')

This is also since 2.2.0 (pinning to 2.1.1 avoids the bug). I have not been able to determine the exact code sphinx-autodoc-typehints trips over. If and when I do, I'll share an example here to help reproduce the problem.

[b-phi]

As requested, some additional info. Will try to find some time to put together a reproducible example

conf.py sections

extensions = [
    'sphinx.ext.autodoc',
    'sphinx.ext.autosectionlabel',
    'sphinx.ext.napoleon',
    'sphinx_autodoc_typehints',
]

# Autodoc Configuration
autodoc_default_options = {
    'members': True,
    'member-order': 'bysource',
    'special-members': '__init__',
    'undoc-members': True,
}

# Typehint Configuration
typehints_defaults = 'comma'
typehints_use_signature = True
typehints_use_signature_return = True

rst where Foo is the one in my original comment

...

.. autoclass:: path.to.class.Foo

[tikuma-lsuhsc]

@b-phi - Thanks. Those options still won't trigger the error, unfortunately. The same goes with @bartfeenstra's conf.py settings in the linked repo.

Meanwhile, I have a fix candidate pushed to my fork:

git+https://github.com/tikuma-lsuhsc/sphinx-autodoc-typehints/tree/fix-issue-462

If possible, could you try the above branch on your projects and see if it resolves the bug?

[b-phi]

Hey @tikuma-lsuhsc, unfortunately this branch does not resolve the error

[tikuma-lsuhsc]

@bartfeenstra - hmm, that's unfortunate. Regarding your error, do you have a snippet of 2.1.1 output which contains 'typing.ParamSpecArgs' (or ParamSpecArgs)? If so, could you point to the line on your repo as well as the expected output text (html or otherwise)? Thanks

[b-phi]

Hey @tikuma-lsuhsc I've created a minimal example. Overriding __eq__ on the metaclass seems to be required to reproduce for me

from typing import Any


class _SchemaMeta(type):
    def __eq__(cls, other: Any) -> bool:
        return True


class Schema(metaclass=_SchemaMeta):
    pass


def f(s: Schema) -> Schema:
    """
    Do something.

    Args:
        s: Some schema.
    """
    return s

[tikuma-lsuhsc]

@b-phi - Confirmed! Thanks for putting the example together.

[tikuma-lsuhsc]

@b-phi & @bartfeenstra - I think I have a solution to the issue. If you could please help me test again with my fork (don't forget to update if tried once above):

git+https://github.com/tikuma-lsuhsc/sphinx-autodoc-typehints/tree/fix-issue-462

Thanks!

[b-phi]

That seems to have fixed it, thanks!

[jmccreight]

This also appears to have fix issues I had (I dont know what they were). Thanks.

[hoodmane]

Closed by #463.